In prior art ear cups of this type, the sealing device is produced from a frame of rigid plastic, a ring of foam plastic and a PVC-film. The ring is placed on the frame, the PVC-film is placed on the ring and is then welded on the frame such that an indivisible unit is formed. The frame of the sealing device is fastened onto the cup portion of the ear cup. The frame and the cup portion are both produced from rigid plastic, whereby rigid material bears against rigid material. If a surface of the frame that bears against the support surface of the cup portion has a shape that differs from the shape of the support surface, this will result in a poor sealing and, thereby, an unsatisfactory noise attenuation. A drawback with such a sealing device is thus that it may allow proportionally much noise to pass through, such that the noise attenuating effect is impaired.